Currently, in order to develop users, mobile operators often conduct promotional activities such as giving away mobile terminals. Such activities not only help expanding the user base, but also help promoting mobile terminal brands, and the users can get mobile terminals at below-market prices or even for free. However, some mobile terminal vendors may obtain such low-priced mobile terminals from one original mobile operator, change the software of those mobile terminals, and then transfer those mobile terminals to other mobile operators' network-coverage areas to be sold at higher prices. This may cause the original mobile operator to suffer losses. Therefore, mobile operators need to restrict the mobile terminals from accessing other networks, and allow the mobile terminals only to be used in a particular range of networks, i.e., network lock.
Certain existing technologies use pure software to implement network lock. Software in a mobile terminal analyzes user information in the subscriber identity module (SIM), such as international mobile identification number (IMSI), etc. If the software in the mobile terminal determines that the user information is in line with the requirements from a corresponding mobile operator, the mobile terminal, such as a mobile phone, is allowed to function properly. If the user information does not meet the requirements, then the user is not allowed to use the mobile terminal.
With the pure software approach, whether or not the network lock mode can be effective is entirely determined by the software. Further, because mobile terminals may be sold in many places, and many different versions of software are concurrently available, it may be easy to find a software version that is not limited by the network lock. A third-party can then update the software in a mobile terminal with a software version without network lock to remove the network-lock function of the mobile terminal. The software in such scheme can be duplicated in a large scale within a short time period, forming a mass production.
The disclosed methods and systems are directed to solve one or more problems set forth above and other problems.